EN ISO 14088:2020

• Abstract:

  This document specifies a test method for the determination of tanning agents through filtration of all vegetable and synthetic tanning products.

• Status: Published
• Publication Date: 07-Apr-2020
• Withdrawal Date: 30-Oct-2020
• ICS: 59.140.30 - Leather and furs
• Technical Committee: CEN/TC 289 - Leather
• Drafting Committee: CEN/TC 289/WG 6 - Test methods for tannery chemicals
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 08-Apr-2020
• Completion Date: 08-Apr-2020
• Ref Project: SIST EN ISO 14088:2020 - Leather - Chemical tests - Quantitative analysis of tanning agents by filter method (ISO 14088:2020)

• Replaces: EN ISO 14088:2012 - Leather - Chemical tests - Quantitative analysis of tanning agents by filter method (ISO 14088:2012)
• Effective Date: 08-Jun-2022
• Refers: ISO 3696:1987 - Water for analytical laboratory use — Specification and test methods
• Effective Date: 09-Feb-2026
• Consolidated By: ISO 14088:2020 - Leather — Chemical tests — Quantitative analysis of tanning agents by filter method
• Effective Date: 12-Feb-2026

Overview

EN ISO 14088:2020 - Leather - Chemical tests - Quantitative analysis of tanning agents by filter method is a CEN-adopted international standard (ISO 14088:2020, IULTCS/IUC 32:2020) that specifies a laboratory method to determine the amount of vegetable and synthetic tanning agents in leather products and tanning materials. The method is an indirect gravimetric analysis that fixes tanning compounds onto low-chromed hide powder and quantifies them after filtration. This edition (2020) supersedes EN ISO 14088:2012.

Key topics and technical requirements

• Scope and principle
  • Quantitative determination of all vegetable and synthetic tanning products using a filter (Procter bell + vacuum filtration) and hide powder absorbent.
  • Principle: fixation of tanning compounds on low-chromed hide powder followed by gravimetric measurement.
• Reagents and limits
  • Distilled water: grade 3 per ISO 3696; pH 5–7; evaporation residue <1 mg per 100 ml.
  • Hide powder: chromium oxide <0.8%, moisture ≤13%; blank value calculated per Annex A; commercial suppliers listed in Annex B.
  • Gelatine solution: 1 g gelatine + 10 g NaCl to 100 ml, pH 4.7.
  • Formic acid: technical grade.
• Apparatus and accuracy
  • Procter bell (specified dimensions), 47 mm sintered glass vacuum filter system, cellulose acetate membrane filters (0.45 µm and 3 µm), drying oven (102 ± 2 °C), analytical balance (0.2 mg precision at 200 g), technical balance (0.1 g at 1 000 g).
• Sample preparation and analysis
  • Representative sampling and homogenization (milling if needed).
  • Preparation of analytical solutions:
    • Vegetable tanning agents: target (4.00 ± 0.25) g/L tannin in solution.
    • Synthetic agents: weigh (4 ± 0.1) g powder or (8 ± 0.1) g liquid into 1 000 ml and dissolve.
  • Steps for detanning, determination of soluble substances, and total solids are specified; calculation and test reporting requirements included.

Applications and users

• Primary users:
  • Leather testing laboratories, tannery quality-control teams, R&D departments, material procurement and specification engineers.
• Practical uses:
  • Verifying tannin content of vegetable extracts and synthetic tanning formulations.
  • Quality control of tanning baths and finished leather to ensure process consistency and product conformity.
  • Supplier qualification, regulatory compliance, and materials characterization for product development.

Related standards

• ISO 3696 - Water for analytical laboratory use (referenced for distilled water quality).
• EN ISO 14088:2020 aligns with IULTCS chemical testing practices and complements other leather testing standards (see national standards bodies and CEN member guidance).

This standard is essential for laboratories performing chemical tests on leather, offering a robust, reproducible filter-method for quantitative analysis of tanning agents.

SLOVENSKI STANDARD
01-junij-2020
Nadomešča:
SIST EN ISO 14088:2012
Usnje - Kemijski preskusi - Kvantitativna analiza sredstev za strojenje s filtrsko
metodo (ISO 14088:2020)
Leather - Chemical tests - Quantitative analysis of tanning agents by filter method (ISO
14088:2020)
Leder - Chemische Prüfungen - Quantitative Analyse von Gerbstoffen durch
Filterverfahren (ISO 14088:2020)
Cuir - Essais chimiques - Analyse quantitative des agents de tannage par la méthode au
filtre cloche (ISO 14088:2020)
Ta slovenski standard je istoveten z: EN ISO 14088:2020
ICS:
59.140.30 Usnje in krzno Leather and furs
71.040.40 Kemijska analiza Chemical analysis
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 14088
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2020
EUROPÄISCHE NORM
ICS 59.140.30 Supersedes EN ISO 14088:2012
English Version
Leather - Chemical tests - Quantitative analysis of tanning
agents by filter method (ISO 14088:2020)
Cuir - Essais chimiques - Analyse quantitative des Leder - Chemische Prüfungen - Quantitative Analyse
agents de tannage par la méthode au filtre cloche (ISO von Gerbstoffen durch Filterverfahren (ISO
14088:2020) 14088:2020)
This European Standard was approved by CEN on 26 March 2020.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 14088:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 14088:2020) has been prepared by Technical Committee ISO/IULTCS
"International Union of Leather Technologists and Chemists Societies" in collaboration with Technical
Committee CEN/TC 289 “Leather” the secretariat of which is held by UNI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by October 2020, and conflicting national standards shall
be withdrawn at the latest by October 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 14088:2012.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 14088:2020 has been approved by CEN as EN ISO 14088:2020 without any modification.

INTERNATIONAL ISO
STANDARD 14088
IULTCS/IUC 32
Second edition
2020-03
Leather — Chemical tests —
Quantitative analysis of tanning agents
by filter method
Cuir — Essais chimiques — Analyse quantitative des agents de
tannage par la méthode au filtre cloche
Reference numbers
ISO 14088:2020(E)
IULTCS/IUC 32:2020(E)
©
ISO 2020
ISO 14088:2020(E)
IULTCS/IUC 32:2020(E)
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
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Phone: [phone]
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Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

ISO 14088:2020(E)
IULTCS/IUC 32:2020(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagents . 1
6 Apparatus . 2
7 Sampling and sample preparation . 4
8 Instrumental analysis . 4
8.1 Preparation of the analytical solution . 4
8.1.1 Vegetable tanning agents . 4
8.1.2 Synthetic tanning agents . 5
8.2 Preparation of the Procter bell . 5
8.3 De-tanning the analytical solution (determination of the non-tanning agents) . 5
8.4 Determination of soluble substances . 6
8.5 Determination of total solids . 6
9 Calculation and expression of the results . 7
10 Test report . 8
Annex A (normative) Determination of hide powder blank value . 9
Annex B (informative) Suppliers of hide powder .10
ISO 14088:2020(E)
IULTCS/IUC 32:2020(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see
www .iso .org/ iso/ foreword .html.
This document was prepared by the Chemical Test Commission of the International Union of Leather
Technologists and Chemists Societies (IUC Commission, IULTCS) in collaboration with the European
Committee for Standardization (CEN) Technical Committee CEN/TC 289, Leather, the secretariat of
which is held by UNI, in accordance with the Agreement on technical cooperation between ISO and CEN
(Vienna Agreement).
IULTCS, originally formed in 1897, is a world-wide organization of professional leather societies to
further the advancement of leather science and technology. IULTCS has three Commissions, which
are responsible for establishing international methods for the sampling and testing of leather. ISO
recognizes IULTCS as an international standardizing body for the preparation of test methods for
leather.
This second edition cancels and replaces the first edition (ISO 14088:2012), which has been technically
revised.
The main changes to the previous edition are as follows:
— Clause 8 (Clause 7 in the first edition) has been extensively revised;
— Annex A from the first edition has been deleted.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved

ISO 14088:2020(E)
INTERNATIONAL STANDARD
IULTCS/IUC 32:2020(E)
Leather — Chemical tests — Quantitative analysis of
tanning agents by filter method
1 Scope
This document specifies a test method for the determination of tanning agents through filtration of all
vegetable and synthetic tanning products.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3696, Water for analytical laboratory use — Specification and test methods
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Principle
Indirect gravimetric analysis of vegetable and synthetic tanning agents through fixing of the absorbent
compounds on low-chromed hide powder.
5 Reagents
5.1 Distilled water, freshly prepared, grade 3 according to ISO 3696.
The pH value of the water shall be between 5 and 7. When using methyl red, the water should not turn
red. The evaporation residue of 100 ml should be less than 1 mg.
5.2 Hide po
...